Binomial expansion and exponential

1.Expand the expression using the Binomial Theorem: ________________

2.Suppose p varies inversely as the square root of q. If p=-7 when q=9, what is p if q is 6?
p=_____

3.The stopping distance d of an automobile is directly proportional to the square of its speed v. A car required 50 feet to stop when its speed was 80 miles per hour. Find a mathematical model that gives the stopping distance d in terms of its speed v.
Your answer is d=_____
Estimate the stopping distance if the brakes are applied when the car is traveling at 62 miles per hour.
Your answer is_____.

Oh i see what i did wrong. I didn't keep track of the negatives. Thanks. What about the others though? #2 i got -4.7 but that seems to be wrong. #3 I'm completely lost. #4 i got y=3/5 which is wrong. #5 i think is all right just want to make sure.